Flexible load bearing structure



Nov. 14, 1961 J. c. BRENEMAN FLEXIBLE LOAD BEARING STRUCTURE Filed Jan. 22, 1960 xix I 9 w I INVENTOR.

United States Patent Office 3,008,702 Patented Nov. 14, 1961 r 3,008,702 FLEXIBLE LOAD BEARING STRUCTURE Joseph C. Breneman, Wooster, Ohio, assignor to Rubbermaid Iuc., Wooster, Ohio Filed Jan. 22, 1960, Ser. No. 4,131 3 Claims. (Cl. 267-1) This invention relates to load supporting structural means and has a special application to such structural means which may be formed of moldable material and molded as a single unit.

A principal object of the invention is to provide such a structural unit having high strength and requisite stiffness for its load bearing function while at the same time having a sufiicient degree of flexibility and resiliency so as to make it useful as a cushioning structure for various purposes.

Another object of the invention is to provide such a structural means which can be formed of suitable moldable material and molded as a single integral unit.

Still another object of the invention is to provide such a structural means which can be molded from various plastic materials including the polyethylenes and vinyls, and various synthetic resin materials.

Another object of the invention is to provide such a structural means which is useful as a cushion packing or packaging material for various purposes. v

Still another object of the invention is to provide such a structural means which can desirably be used as a cushion seat or cushion back in various applications for the sea-ting of persons in automobiles, airplanes, chairs and the like.

A further object of the invention is to provide such a structural means which is useful as a packing material for packages which are to be dropped from airplanes by parachutes and the like and providing a cushion packaging material for this purpose which is desirably flexible and resilient but which is of suflicient strength to minimize breakage of the material or damage to the contents of material packaged thereby when subjected to large impact shocks resulting from such use.

A further object of the invention is to provide such a A structural means which is so designed as to permit passage of air therethrough in various directions so as to be capable of providing desirable ventilating characteristics when used as a seat cushion.

Other objects, advantages and features of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a top plan view of a structural unit embodying the invention.

FIGURE 2 is a bottom plan view of the same.

FIGURE 3 is a sectional View taken on the line 3--3 of FIGURE 1.

Now referring to the drawings, the structural means of the invention is designated as a Whole therein by the numeral 1 and comprises a unitary web having openings therethrough and a plurality of load supporting columns joined to said web and extending therefrom in a direction perpendicular to the plane of the web. As shown by the exemplification illustrated in the drawings, the structural unit 1 may be formed of a plurality of basket-like column units individually designated by the numeral 2. In said exemplification, each of said column units comprises an upper circular rim or open frame member 3, of major or larger diameter, a solid bottom part or base member 5 of smaller diameter, and a plurality of of equidistantly spaced connecting members or strut members 4 extend- .ing between the rim or frame member 3 and the base 5,

said strut members being joined to said rim 3 and to the base 5 adjacent the peripheral edge 5a of the latter.

Each of the column units 2 has only its rim 3 joined to the of adjacent column units 2, the rims 3 being dis posed in a common plane forming a unitary web having openings therethrough. The other parts 4 and 5 of each column unit 2 are separated from the corresponding parts of the other column units 2 and thus provide separated columns joined to the web formed by the connected rim members 3, said columns extending from the web in a direction perpendicular to the plane of the web.

The unitary structural means 1 disclosed herein may be conveniently molded of any suitable moldable material. 1 preferably mold the structural means 1 of a suitabl plastic material which is capable of providing the desired strength and stiffness to enable the same to perform its load bearing function and yet provide desired flexibility and resiliency to enable the structural means 1 to serve as a cushioning structure for use as a seat cushion or as a packaging material of the type above referred to.

For the foregoing reasons I preferably mold the structural unit 1 of a suitable polyethylene composition described as follows:

Monsanto polyethylene 935 Specific gravity (ASTM D792-50 test)=0.92

Melt index (ASTM D-1238-52 T test)=7.0

Softening temperature=22l230 F.

Tensile modulus (ASTM D-638-52 T test)=22,000 p.s.i.

Hardness, shore (ASTM D-67 6-49 T test) =C-73 Apparent (bulk) density (ASTM D-1l8254)=33 lbs./

cu. ft.

From the foregoing it will be understood that the integrally joined rims 3 eifectively provide a continuous integral web constituting the top portion of the single integral structural unit 1 with the other portions of the individual basket-like units projecting downwardly from said web. When the structural unit 1 is suitably molded from the polyethylene composition herein specifically described, said unit has a high degree of flexibility and resiliency such that portions of the unit 1 may be readily moved, rolled, or bent about any axis in the plane of the integral web provided by the conjoined rims 3 and the structural unit will readily spring back to its original shape when such rolling or bending pressures are released therefrom. At the same time it will be understood that the structural unit so molded from such polyethylene composition provides 'a strong, stiff and relatively rigid load bearing structure in its vertical direction, a structure which will support a considerable load applied thereto in a direction perpendicular to the plane of the upper surface or web thereof without deformation but which nevertheless provides a structure having the desired degree of flexibility and resilience making it suitable for various uses herein referred to including the use as a seat cushionl and the use as a cushion packing or packaging mate- 1'13 It should be further noted that the construction of the structural unit 1 provides numerous openings therethrough in various directions enabling air circulation therethrough to a very high degree which is advantageously availed of for ventilation purposes when the structure is employed as a seat cushion, such ventilation serving to increase the comfort of the user particularly in hot weather.

I claim:

1. A structure of the class described, comprising a unitary web having openings therethrough, and a plurality of load supporting columns joined to said web and extending therefrom in a direction perpendicular to the plane of the web, each of said columns comprising a base member and a plurality of strut members extending between said base member and said Web and joined to said base member and to said web, said structure being formed entirely of moldab-le material having some resiliency when molded, said structure having a high degree of resistance to compression in a direction perpendicular to the plane of said web.

2. A structure of the class described comprising a plurality of basket-like load supporting column units, each of said units comprising an upper continuous rim, a base member, and a plurality of spaced strut members extending between said rim and said base member and joined to said rim and to said base member adjacent the peripheral edge thereof, the rims only of said column units being joined to one another to form an integral web from which the columns formed by the respective base members and their conjoined strut members extend in a direction perpendicular to the plane of said web, said structure being formed entirely of moldable material having some resiliency when molded, said structure having a high degree of resistance to compression in a direction perpendicular to the plane of said Web.

3. A structure of the class described comprising a plurality of basket-like load supporting column units, each of said units comprising a circular continuous rim, having an opening arially therethrough, a circular base member, and a plurality of spaced strut members extending between said rim and said base and joined to said rim and to said base adjacent the periphery of the latter, whereby said strut members are arranged in substantially circular columnar disposition, the rims only of said column units being joined to one another to form an integral Web from which the respective columns formed by the respective base members and their conjoined strut members extend in a direction perpendicular to the plane of the web, said structure being formed entirely of molda-ble material having some resiliency when molded, said structure having a high degree of resistance to compression in a direction perpendicular to the plane of said web.

References Cited in the file of this patent UNITED STATES PATENTS 1,464,716 King et al Aug. 14, 1923 2,141,112 Neupert Dec. 20, 1938 2,440,150 Mitchell Apr. 20, 1948 2,768,924 Wright Oct. 30, 1956 

